JPS6320364A - Spiro-benzanthracenephthalide compound, production thereof and color forming recording medium containing said compound - Google Patents

Abstract

NEW MATERIAL:Spiro-benzanthracenephthalide compds. of formula I, wherein R<1>, R<2>, R<3>, R<4>, R<5> and R<6> are each a member selected from the group consisting of a (lower alkoxy-substd.) lower alkyl, a 5-6C cycloalkyl or a (lower alkyl- or lower alkoxy-substd.) aralkyl, aryl, etc. EXAMPLE:6, 4', 10'-Tris( dimethylamino )-spiro-[7H-benz[de]anthrac-ene-3,7'-phthali de. USE:Color forming dyes which form a color by the action of an acid material, absorb at a high absorption ratio electromagnetic waves in the region of visible to near infrared light and are suitable for use in the production of recording paper. PREPARATION:One mol of a phthalide compd. of the formula is subjected to dehydrocyclization in the presence of at least one mol of a Friedel-Crafts catalyst (e.g., aluminum chloride) to obtain the spiro-benzanthracene-phthalide compd. of formula I.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a color-forming dye that develops color by the action of an acidic substance and absorbs electromagnetic waves ranging from the visible region to the near-infrared region, a method for producing the color-forming dye, and a method for producing the color-forming dye. Chromogenic recording material containing an acidic substance (related to).

Although it is colorless or almost colorless in itself, it is a color-forming system consisting of a color-forming dye (hereinafter referred to as "color-forming dye") that develops color under the action of an acidic substance, and an acidic substance (color developer) that develops the color. The recording medium used is widely used, for example, pressure-sensitive copying paper, heat-sensitive recording paper, etc.

Also, with the recent development of electronics, for example, P.
The scope of use of color-forming dyes is expanding, such as by creating barcodes at the user's stage in the OS and reading them using electromagnetic waves emitted by semiconductor lasers.

Therefore, there is a demand in the industry for a color-forming dye that not only absorbs 'N and m-waves in the visible region, but also absorbs near-infrared electromagnetic waves emitted by semiconductor lasers.

Phthalide-based dyes that form pigments that absorb electromagnetic waves from the visible region to the near-infrared region during color development are disclosed in JP-A-51-121035 and JP-A-51.
-121037, JP 51-121038, JP 55-115448, JP 55-115449, JP 55-115450, JP 55-1154
No. 51, JP-A-55-115452, JP-A-55-1
No. 15456, JP-A-57-167979, JP-A-5
8-157779, JP-A No. 60-8364, JP-A-60-27589, etc., and thiofluorane compounds are known from JP-A No. 59-148695. is JP-A-59-1
No. 99757 and Japanese Unexamined Patent Publication No. 60-226871.

The present inventors have discovered that the action of acidic substances (therefore, the pigment produced is
I! As a color-forming dye with a novel structure that absorbs 1 from the visible region to the near-infrared region of magnetic waves, it has the general formula (wherein R1, R2, R3, R4, R5 and R6 are each independently substituted with a lower alkoxy group). a lower alkyl group; a cycloalkyl group having 5 or 6 carbon atoms; or an aralkyl group or an aryl group optionally substituted with a lower alkyl group or a lower alkoxy group; R6 may form a pyrrolidino, piperidino or morpholino ring with the nitrogen atom to which they are attached, and R7, R8, R9 and HIO represent a lower alkyl group, a lower alkoxy group or a trifluoromethyl group)
We discovered that the new spirobenzanthracenephthalide compound, which has the following properties, is a color-forming dye that develops color under the action of acidic substances and absorbs electromagnetic radiation from the visible region to the near-infrared region.

Accordingly, the present invention relates to a method for producing a spirobenzanthracene hetthalide compound represented by the above general formula (1) and a method for using the same.

The compound of the general formula (1) has the general formula (wherein R1, R2, R5, R4, R5, R6, R7,
R8, R9 and R10 are the same as above)) The 7-thallide compound can be produced by subjecting it to dehydrogenation ring closure under the action of a Friedel-Crafts type catalyst. The alkyl group of the lower alkyl group and the lower alkoxy group in the general formulas (1) and (II) has 1 to 8 carbon atoms and is a straight chain or branched chain group.

These spirobenzanthracenephthalide compounds form a color-forming system with an acidic substance in the same way as conventionally known thiofluorane-based or fluorene-based color-forming dyes to form a recording medium, and are widely used as pressure-sensitive and heat-sensitive recording papers. can do.

Several examples of the spirobenzanthracenephthalide compound represented by the general formula (1) are listed in Table 1, but the invention is not limited to these.

Table 1 Spirobenzanthracene 7 represented by general formula (1)
Table 1 shows the color tone reflection curves after color development due to the action of the talide compound dispersion. This is the curve obtained according to Example 2.

The spirobenzanthracenephthalide compound represented by the general formula (1) develops a color due to the action of an acidic substance, and its color development is due not only to its absorption in the near-infrared region of Xa waves, but also to its extremely high absorption rate. It has the remarkable property of being large and robust to light. That is, as shown in FIG. 3 obtained by the experiment 114, although the amount of this spirobenzanthracene compound used was 179 times the amount of the fluoran compound used in combination, the curve a in FIG. The absorption coefficients of b and C near 860 nm correspond to the visible wavelength portion of the curve, i.e. 400 nm.
It is approximately 70% or more of the absorption rate at ~600 nmK. Furthermore, as is clear from FIG. 4 showing the results of the light emitting test in Example 5, the coloring of the compound represented by general formula (1) still shows satisfactory absorption in the near-infrared region even after 5 hours of light irradiation using a needle tip tester. Because it has.

Spirobenzanthracene 7 represented by general formula (1)
The thalide compound is obtained by dehydrogenating the 7-thalide compound represented by the general formula (1) with a 7-Riedel-Crafts catalyst, and the amount of the 7-Riedel-Crafts catalyst used in this case is as follows: Phthalide compound 1
A 1 molar ratio or more is required for the molar ratio. Friedel-Crafts type catalysts include aluminum chloride,
Antimony chloride, ferric chloride, tellurium chloride, tin chloride, titanium chloride, bismuth chloride, zinc chloride (all anhydrous), boron fluoride, sulfur trichloride, sulfur pentachloride, sulfur oxychloride, phosphorus pentoxide, phosphoric acid, poly9 phosphoric acid, hydrochloric acid, sulfuric acid,
Examples include acetic acid, trifluoroacetic acid, and aluminum chloride-sodium chloride complex salt. These catalysts may be used alone or in combination.

The reaction may be carried out by mixing and melting the phthalide compound and the 7-Riedel catalyst, but it is advantageous to carry out the reaction in an organic solvent in order to facilitate the preparation of the reaction. As the organic solvent, solvents commonly used in the 7-Liedl-Crafts reaction, such as trichloroethane, tetrachloroethane, tetrachloroethylene, nitrobenzene, dichlorobenzene, and trichlorobenzene, are used.

The reaction temperature is approximately 100°C to 200°C.
A temperature range of 20°C to 150°C is suitable, and the reaction is completed in about 1 hour in most cases.

In addition, the phthalide compound of the general formula (l) is, for example, %
It can be manufactured according to the method described in Japanese Patent No. 5746.

-ff Color-forming recording materials using the spirobenzanthracenephthalide compound of formula (1) include recording materials for pressure-sensitive copying or heat-sensitive recording, such as thermal transfer, current recording, electrophotography, and photosensitive recording. , used for recording bodies used in ultrasonic recording, electrostatic recording, photosensitive printing, etc.

The method of using the compound of general formula (1) for these recording materials is the same as the method of using conventionally known color-forming dyes. For example, acid clay, activated clay, attapulgite,
Bentonite, colloidal silica, inorganic acidic substances such as aluminum silicate, benzoic acid, p-tert-butylbenzoic acid, phthalic acid, gallic acid, salicylic acid, 5-isopropylsalicylic acid, 3-phenylsalicylic acid, 3-cyclohexylsalicylic e, s, s-tert-butylsalicylic acid, 5-methyl-5-benzylsalicyl ff
i, 3-pheni-5-<α.

α-dimethylbenzyl) salicyl &, 3,5-di(2
-methylbenzyl)salicylic acid, 2-hydroxy-1-
Aromatic carboxylic acids such as benzyl-3-naphthoic acid, salts of these aromatic carboxylic acids with metals such as zinc, magnesium, aluminum, and titanate, phenols such as p-phenylphenol-formalin resin, p-butylphenol-acetylene resin, etc. A resin color developer, a mixture of these phenolic resin color developers and the metal of the aromatic carboxylic acid, and further bisphenol A, 4t4'-5ec
-Bisphenol compounds such as butylidene bisphenol, 4,4'-cyclohexylidene bisphenol, 2,2'-dihydroxyldiphenyl, intamethylene-bis(4-hydroxybenzoate), 1,7-bis(
4-hydroxyphenylthio)-3,5-E; sulfur-containing bisphenol compounds such as oxaheptane, benzyl 4-hydroxybenzoate, ethyl 4-hydroxybenzoate, propyl 4-hydroxybenzoate, isopropyl 4-hydroxybenzoate , 4-hydroxybenzoic acid esters such as butyl 4-hydroxybenzoate, isobutyl 4-hydroxybenzoate, chlorobenzyl 4-hydroxybenzoate, methylbenzyl 4-hydroxybenzoate, diphenylmethyl 4-hydroxybenzoate, 4- Hydroxydiphenylsulfones such as hydroxy-4'-methyldiphenylsulfone, 4-hydroxy-4'-isopropoxydiphenylsulfone, 4-hydroxy-4'-phthoxydiphenylsulfone, dimethyl 4-hydroxy7talate, 4-hydroxy 4-hydroxyphthalic acid diesters such as dicyclohexyl heptatarate and 4-hydroxyphthalate diphenyl, e.g. 2-hydroxy-6
- ester acids of hydroxynaphthoic acids, such as carboxynaphthalene, and also gallic acid lauryl ester;2.
Examples include 2-bis(4-carboxyphenyl)hexafluoropropane, zinc thiolbenzoate hydroxyacetophenone, p-phenylphenol, benzyl 4-hydroxyphenylacetate, p-benzylphenol, and hydroquinone monobenzyl ether.

U.S. Pat. No. 2,548,365 and U.S. Pat.
No. 2.800.457, No. 2.800,45
Pressure-sensitive copying paper can be produced according to the method described in JP-A-58-112041 or JP-A-58-139738.

Pressure-sensitive copying paper consists of an upper sheet on which microcapsules containing an organic solvent for a color-forming dye are coated and carried on the lower surface, and a lower sheet on which a color developer (acidic substance) is coated and carried on the upper surface. unit (inner paper carrying color developer on the top surface and microcapsules on the bottom surface may also be included in the unit), or microcapsules and color developer are coated on the same paper surface. It may be a so-called self-content paper.

As the organic solvent, there is used an inert and nonvolatile organic solvent that dissolves the color-forming dye well, such as diphenylmethane, alkylnaphthalene, or alkyltriphenyl.

The method for producing heat-sensitive recording paper using the compound of general formula (1) is the same as that for known color-forming dyes.
Special Publication No. 45-14039 or Japanese Patent Publication No. 59-708
It can be manufactured according to the method described in Publication No. 7 and the like.

That is, for example, a suspension of fine particles of the compound of the general formula (1) of the present invention or a mixture thereof with another color-forming dye and fine particles of an acidic color developer substance dispersed in an aqueous solution of a water-bathable binder is placed on paper. By coating and drying, heat-sensitive recording paper with excellent color development can be obtained. When a sensitizer is added to the above suspension, a heat-sensitive recording paper with extremely high sensitivity can be obtained. This suspension further contains fillers, dispersants, color image stabilizers, antioxidants, desensitizers, antiblocking agents, antifoaming agents,
Light stabilizers, fluorescent brighteners, etc. may also be included.

Examples of water-soluble binders used in this case include hollyhinyl alcohol, hydroxyethyl cellulose, carboxymethyl cellulose, styrene-maleic anhydride copolymer salt, styrene-butadiene emulsion, vinyl acetate-
Sensitizers include, but are not limited to, maleic anhydride emulsions, polyacrylates, polyacrylamides, starches, casein, gum arabic, etc. Examples of sensitizers include higher fat dispersions, benzamides, etc. , stearic acid/anilide, acetoacetate, thioacetanilide, dimethyl phthalate, dibenzyl terephthalate, dibenzyl inphthalate, bis(tert-
butylphenol) a, 91j, such as 4,4'-dimethoxydiphenylsulfone, 4-1so-propoxy-4'
-n-butoxysulfone, 4,4'-dibutoxydiphenylsulfone, 4,4'-di-n- (or iso
-) are diethers of bisphenol S such as methyloxydiphenylsulfone, diphenylamine, carbazole, 2.3-di-m-tolylbutane, 4.4'
-dimethylbiphenyl, di-β-7tylphenylenediamine, and the like.

Examples of fillers include clay, talc, kaolin, satin white, titanium oxide, calcium carbonate, magnesium carbonate, barium sulfate, magnesium silicate, and aluminum silicate. Further, dispersants include sulfosuccinic acid esters such as dioctyl sodium sulfosuccinate, sodium totecylbenzenesulfonate, sodium salts of lauryl alcohol sulfate, fatty acid salts, etc., and color image stabilizers include salicylic acid derivatives, Metal salts (especially zinc salts) of oxynaphthoic acid derivatives and zinc compounds insoluble in pond water are used as antioxidants, such as 2,2'-methylenebis(
4-methyl-6-tert-butylphenol), 2,
2'-methylenebis(4-ethyl-6-tert-butylphenol), 4,4'-furobylmethylenebis(6
-methyl-6-tert-butylphenol), 4.4
'-thiobis(2-tert-butyl-5-methylphenol), etc., desensitizers such as aliphatic higher alcohols, polyethylene glycol, guanidine derivatives, etc., and anti-blocking agents such as stearic acid, zinc stearate, etc. , calcium stearate, carnauba wax, paraffin wax, etc.

To use the compound of general formula +11 for thermal transfer, for example, JP-A-58-212985, JP-A-59-33185,
%Kokai No. 59-42995 or JP-A No. 59-225
It can be used according to the method described in Japanese Patent Publication No. 986, and for use in energized recording paper, for example, Japanese Patent Application Laid-Open No. 8-961
No. 37, JP-A No. 48-ICN935 or JP-A No. 4
For use in electrophotography, it can be used according to the method described in Japanese Patent Application Laid-Open No. 52-24530 or Japanese Patent Application Laid-Open No. 52-56932.

Furthermore, to use the compound of the present invention for photosensitive recording, for example, Japanese Patent Publication No. 3B-24188, Japanese Patent Publication No. 45-10550, Japanese Patent Publication No. 45978-1978, and Japanese Patent Publication No. 80120-1989.
No., JP-A-50-126228, JP-A-52-141
It can be used according to the method described in No. 633 or JP-A-54-TA7829. In this case, examples of acid precursors that generate protonic acids or Lewis acids depending on the energy aK include organic halogen compounds (which can also be sensitized with amine compounds) and diazonium salts described in JP-A-55-13780. In addition to iodonium salts, sulfonium salts such as dimethylphenacylsulfonium hexafluorosinate ah or triphenylsulfonium hexafluoroantimonate (V) salt are used.

French Patent No. 2.120 for use in ultrasonic recording
．． No. 922, K used for electrostatic recording was published in Special Publication No. 49-393.
No. 2, for use in photosensitive printing materials, JP-A-48-1210
It can be used according to the method described in Publication No. 4.

Recording paper manufactured according to these methods can be provided with a protective layer on its surface if necessary, and an adhesive layer can be provided on the back side of the paper to make it convenient to use as a label. Records manufactured according to this method are used not only for the barcodes mentioned above, but also for copying books and documents, computers, facsimile machines, ticket machines, labels, etc. , or for example, to prevent false documents, where information in company records cannot be seen with the naked eye.
It can be applied to anti-duplication, unlocking devices, laser discs, etc., and has a wide range of applications.

In these recording materials, the spirobenz 7thracenephthalide compound of general formula (1) is used alone or in a mixture of several types thereof, and also known color-forming dyes, such as 3-diethylamino-6- Methyl-7-phenylaminofluorane, 5-N-methyl-cyclohexylamino-6-methyl-7-phenylaminofluorane, 3-
N-Methyl-n-i lopylamino-6-methyl-7-phenylaminofluorane, 3-N-- Black color-forming compounds such as m-9fluoromethylphenylaminofluorane, 3-di-n-butylamino-7-chlorophenylaminofluorane, 3-N-ethyltoluidino-6-methyl-7-phenylaminofluorane, etc. Dye, crystal violet lactone, penzoyl leucomethylene blue, 5
(or 7)-(1-octyl-2-methylindol-5-yl)-5-(or 7)-(4-diethylamino-2-ethoxyphenyl)-5,7-cyhydroxyfluoro(3,4- b)-pyridine-7 (or 5)
Blue-coloring dyes such as -one, 3-diethylamino-5
-Methyl-7-dibenzylaminofluorane, 3-N-
Green coloring dyes such as inbutyl-ethylamino-7-phenylaminofluorane, 5-diethylamino-6-
Methyl-7-/rolofluorane, 3-cyclohexylamino-6-chlorofluorane, 5-N-inbutyl-ethylamino-6-methyl-7-chlorofluorane, 5-
N-Inbutyl-ethylamino-7-chlorofluorane, 3-N-Inbutyl-ethylamino-7-methylfluoran, 3-N-isobutyl-ethylamino-5,6-
It can also be used in combination with a red coloring dye such as benzofluorane.

Furthermore, the compound of general formula (1) can also be used in combination with other types of color-forming dyes that produce pigments that absorb electromagnetic waves ranging from the visible region to the near-infrared region during color development; examples of such color-forming dyes include, for example. Examples include the phthalide-based, thiofluorane-based, and fluorene-based compounds shown in the prior art section. Furthermore, K is the patent application No. 126149 of 1980, the patent application No. 215212 of 1982, the patent application No. 224955 of 1982, and the patent application No. 24 of 1983 related to FJIK from the present applicant.
It is also possible to use it in combination with the compounds described in No. 7135 or the compounds described in Japanese Patent Application No. 60-229981.

The compound of general formula (1) can also be used in combination with dyes or pigments that do not absorb near-infrared electromagnetic waves. This combination is effective in modifying the pale gray-yellow coloring that tends to occur in chromogenic recording materials produced using the compound of general formula (1).

When the compound represented by the general formula (1) of the present invention is used in color-forming recording materials such as pressure-sensitive copying paper and heat-sensitive recording paper, it develops a color tone that absorbs electromagnetic waves ranging from the visible region to the near-infrared region. Therefore, it can be applied to information reading devices using semiconductor lasers, and has the effect of expanding the range of uses of color-forming recording materials.

Example 1 (Synthesis example) 3-(4'-Q methylaminophenyl>-5-(4'-
(dimethylaminonaphthyl)-6-dimethylaminophthalide 2&5g and anhydrous aluminum chloride 5A2N and 1
．． L2.2-tetrachloroethane 200- was charged into 7 flasks, and the temperature was gradually raised while stirring to 115° to 150°C.
After continuing the reaction at a temperature of 1 hour, the reaction mixture was placed in an ice-water trap.

After removing the solvent by steam distillation, the precipitate is separated, dissolved in toluene, washed with 20 drops of an aqueous solution of caustic soda, and then washed with water. The toluene layer is concentrated and cooled to precipitate crystals. 6. Recombine with toluene.
4',10'-tris(dimethylamino)-spiro-[7H-benz(do) anthracene-3,7'-
7Thallide] 12.0.9 was obtained as pale yellow crystals with a decomposition point of 190-200°C. The infrared absorption spectrum of this crystal is shown in FIG.

Example 2 The spirobenzanthracenephthalide compound produced in Example 1 was dissolved in toluene, and the solution was dropped onto clay-coated bottom paper and resin-coated bottom paper for pressure-sensitive copying paper. was colored pale gray-green. This chromogenic surface reflection curve was plotted using a spectrophotometer-integrating sphere. The results are shown in Figure 2.

Example 3 (Pressure-sensitive copying paper) 6.4',10'-)lis(dimethylamino)-spiro-[7H-benz(de)anthracene-3,7'-phthalide) 1. O, t9 is alkylnaphthalene 20.
? The mixture was heated to 90°C and dissolved (liquid A). On the other hand, gelatin (isoelectric point 1) 2.0.9 and carboxymethyl cellulose α511 were completely dissolved in water at 120 dK (solution B).

Next, liquid A and liquid B were mixed at 50 to 60°C and stirred at high speed to emulsify, and the sound was adjusted to +5 to 9 OK. After adjusting ≠, stir at high speed for 20 minutes, then gradually add dilute acetic acid...
Lower the temperature to 58°C, cool to 5-10°C while continuing to stir,
Add formalin (37%) solution 61 and 10-2
Stirring was continued for an additional hour at 0°C.

Then, the pH was adjusted to 9 using an aqueous sodium hydroxide solution (5%).
, adjusted to 0. This emulsion was slowly stirred for several more hours to form extremely fine capsules [internal K 6,4',10'-)lis(dimethylamino)-
Spiro-[7H-benz(do)anthracene-3,7
An emulsion containing an alkylnaphthalene solution of '-7 talide] was obtained. This emulsion was applied to paper and dried to prepare a top sheet of pressure-sensitive copying paper. On the other hand, a phenol-formalin resin was applied to paper and dried to prepare a lower paper. When the coated surface of the top paper was placed on the coated surface of the bottom paper and pressure was applied to a portion thereof, that portion of the bottom paper developed a pale gray-green color. The reflection curve of this part had almost the same shape as that obtained in implementation flJ1.

Example 4 6.4',10'-)lis(dimethylamino)-spiro-[7H-benz(de)anthracene-6,7'-phthalide) 1.019 and 3-N-cyclohexyl-methylamino-6 - Methyl-7-7 enylaminofluorane (black coloring dye) 901, and this mixture 55
I, 15% aqueous solution of polyvinyl alcohol (Kuraray Co., Ltd., "Kuraray-105J") 41.5.9. Clay (Engelhard Co., Ltd., rUW-90J) 15.0.9 and pure water 4α09 were added to glass beads (diameter 1~ 1.5 times) 1s
(Put it in a 250 g Ll polyethylene bottle with [', seal it, and attach it to a Red Devi1 paint conditioner, shake it at a frequency of 630 times/min for 5 hours, remove the glass beads, and mix the above mixture. An aqueous suspension was obtained (Suspension A).

On the other hand, as a color developer, bisphenol A10. 15 aqueous solution of polyvinyl alcohol (same as above) 41. S
L clay (same as above) aO, F and pure water 4αO11
Put it in a 250mm polyethylene bottle with Glass Peas 150J, seal it tightly, and add Indian conditioner to 660mm.
After shaking at a frequency of vibrations/min for 8 hours, the glass beads were removed to obtain an aqueous suspension of bisphenol A (NIA
Turbid liquid B).

10. each of A liquid and B liquid. F was mixed and stirred for 20 minutes to produce a coating solution.

This coating solution was applied to a white base paper using a wire rod 12 and dried for 2 minutes with warm air at 60° C. to produce thermal recording paper I. The coated surface of this heat-sensitive recording paper was slightly grayish-yellow.

The coated surface of this thermosensitive recording paper was heated for 5 seconds at a temperature of 150° C. using a thermal gradient tester (manufactured by Toyo f#ki Seisakusho Co., Ltd.). The heated area turned black.

The reflection curve of this colored portion was drawn using a spectrophotometer-integrating sphere. The results are shown in Figure 3.

In addition, FIG. 6 shows thermal recording paper (each with a small size Reflection curves of the coloring surfaces of heat-sensitive recording paper and III) heated and colored in the same manner as above, and the mixture &5! 3 instead of i
-N-cyclohexylmethylamino-6-methyl-7-
The reflection curve of the colored surface of 9 thermosensitive recording paper (color developer is bisphenol A) (thermal recording paper ■) produced in the same manner using phenylaminofluorane 3.5I is also described. .

Example 5 Thermal recording paper described in Example 4 1. The colored surfaces of I, ill and ■ were irradiated with light for 5 hours using a light emitting tester (carbon arc type), and their reflection curves were measured.

The results are shown in Figure 4. Comparing Figure 4 with Figure 5, it can be seen that the coloring obtained from the compound of the present invention still has sufficient absorption in the near-infrared region around 850 nm even after irradiating the source of the carbon arc for 5 hours. .

[Brief explanation of the drawing]

Figure 1 shows 6.4', 10'-)lis(dimethylamino)
-spiro-(7H-benz[de]anthracene-3,
7'-phthalide]. FIG. 2 shows two types of reflection curves obtained in Example 2, where curve a is the reflection curve for color development by clay (activated clay), and curve A is the reflection curve for color development by phenolic resin. FIG. 3 shows the reflection curves of the coloring surfaces of the four types of thermal recording paper obtained in Example 4, and curve C is the reflection curve of the coloring surface of the thermal recording paper I.
Curve d is the reflection curve of the thermal recording paper (2), curve e is the reflection curve of the thermal recording paper (I), and curve fFi is the reflection curve of the coloring surface of the thermal recording paper (2). FIG. 4 shows the reflection curves of the coloring surface of the thermal recording paper 4a subjected to the light emitting test according to Example 5, where the curve C' is the curve C' of the thermal recording paper I, the curve d' is the curve e of the thermal recording paper 1, and the curve e ' is the reflection curve of the thermal recording paper (2), and curve f' is the reflection curve of the coloring surface of the thermal recording paper (2) after the stylus test. Patent applicant: 2 people other than Shinnichi 1 Kako Co., Ltd.

Claims (1)

[Claims] 1) General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (In the formula, R^1, R^2, R^3, R^4, R^5 and R^6 are each independent represents a lower alkyl group which may be substituted with a lower alkoxy group; a cycloalkyl group having 5 or 6 carbon atoms; or an aralkyl group or an aryl group which may be substituted with a lower alkyl group or a lower alkoxy group, and R^1 and R^2, R^3 and R^4, R^5 and R^6 together with the nitrogen atom to which they are bonded may form a pyrrolidino ring, piperidino ring or morpholino ring, and R ^7, R^8, R^9 and R^1^0 represent hydrogen, a lower alkyl group, a lower alkoxy group or a trifluoromethyl group). 2) General formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (In the formula, R^1, R^2, R^3, R^4, R^5 and R^6 are each independently substituted with a lower alkoxy group a cycloalkyl group having 5 or 6 carbon atoms; or an aralkyl group or an aryl group which may be substituted with a lower alkyl group or a lower alkoxy group; 2. R^3 and R^4, R^5 and R^6 may form a pyrrolidino ring, piperidino ring or morpholino ring together with the nitrogen atom to which they are bonded, and R^7, R^8 , R^9 and R^1^0 represent hydrogen, a lower alkyl group, a lower alkoxy group, or a trifluoromethyl group) by the action of a Friedel-Crafts type catalyst to dehydrogenate and ring-close the phthalide compound. Characteristic general formulas▲There are mathematical formulas, chemical formulas, tables, etc.▼ (In the formula, R^1, R^2, R^3, R^4, R^5, R
^6, R^7, R^8, R^9 and R^1^ are the same as above). 3) General formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (In the formula, R^1, R^2, R^3, R^4, R^5 and R^6 are each independently substituted with a lower alkoxy group a cycloalkyl group having 5 or 6 carbon atoms; or an aralkyl group or an aryl group which may be substituted with a lower alkyl group or a lower alkoxy group; , R^3 and R^
4. R^5 and R^6 may together with the nitrogen atom to which they are attached form a pyrrolidino, piperidino or morpholino ring, and R^7, R^8, R^9 and R^1 ^0 represents hydrogen, a lower alkyl group, a lower alkoxy group, or a trifluoromethyl group) A spirobenzanthracenephthalide compound and an acidic substance that causes the compound to develop color. .